Cooling tube for dynamo-electric machines



Dec. l; 1936. l P. A; H. MossAY COOLING TUBE FOR DYNAMO-ELECTRICMACHINES Filed March 28, 1934 5 Sheets-Sheet l Dec. l, 1936. P. A. H.MossAY COOLING TUB FOR DYNAMO-ELECTRIC MACHINES 5 Sheets-Sheet 2.[/w/./vra/Q I 73M No# Filed March 28, 1934 Dec. 1,1936. p A, MOS'SAY l2,062,470

COOLING TUBE FOR DYNAM0-ELECTR1C MACHINES 3 Sheets-Sheet` 3 Filed March28, 1934 Patented Dec. l, 1936 UNITED STATES PATENT GFFICE Paul AlphonseHubert Mossay, Norwich, England Application March 28,

1934, Serial No. 717,696

lin Great Britain April 3, 1933 1d) Claims.

The invention relates to cooling tubes through which the internal air ofan enclosed electric dynamo machine is circulated and cooled by colderair blown over the outsides of the tubes, and particularly to thosetubes which are made of sheet metal and shaped to an approximatelyrectangular cross-section, the ends of the tube being provided withbends for insertion into sheet metal cylinders or segments enclosing themachine near each end thereof.

The objects of the invention are to effect economy in manufacture whileensuring efcient jointing of the parts of the tubes, and between thetubes and the cylindrical parts or segments in which their ends areinserted so as to minimize leakage of dust laden air into the tubes orinto the machine, and to increase further the strength and rigidity ofthe tubes and also to increase the cooling surface.

A cooling tube according to the invention is composed of two similardished parts stamped or presse-d out of sheet metal, preferably having astraight portion and two end bends, and provided with perimetral anges,the two parts being placed together with the flanges in correspondingrelation with intermediate strips or plates between the anges. When thetubes are made of steel, the parts are prefer-ably welded together, forexample, by spot or seam welding, but if made of other metal, they maybe soldered or brazed or hot galvanized.

The intermediate plate increases the thickness of the combined flanges,so that the slotted cylindrical casing parts or segments, in which theend bends of the tubes are inserted, can be efficiently punched withslots to receive the Bauges.

The intermediate plate increases the internal cooling surface and inorder further to increase the cooling surface, the plate may extendbeyond the anges of the dished parts of the tubes and, if desired,beyond the ends of the tubes and, therefore, beyond the end shields ofthe machine, so as to act as cooling ins as well as a diffuser thatensures an even distribution of the cooling air between the tubes.

The dished parts oi the tubes provided with end bends are preferablytapered, so that when the end bends are forced into the slots in thecylindrical casing segments or other parts of the machine by a wedgingaction, a tight iit is ensured.

In the drawings:

Figure 1 is a side view of a cooling tube, partly broken away at one endto show the intermediate plate, and

Figure 2 is an inverted plan of the tube.

Figure 3 is a cross-section on the line III-III of Figure 1.

Figure 4 is a similar cross-sectional view of another form of tube.

Figures 5 and 6 are, respectively, a plan and side view of a portion ofa cooling tube xed in a portion of a slotted cylindrical casing segment.

Figure '7 is a side view of a portion of a still further form of tube.

Figure 8 is a side sectional elevation of part of an enclosed dynamoelectric machine, showing one cooling tube in position.

Figure 9 is an end sectional elevation of part of the machine shown inFigure 8, the section being taken on the line IX-IX, Figure 8.

ln the examples illustrated, each tube comprises two dished parts l and2 stamped or pressed from sheet steel, each of these parts having astraight channel 3, end channels or bends Ll and 5, and a flatperimetral flange 6, except at the edges l which are to surround theopen ends of the tube.

The two parts i and 2 may be placed together, with their flanges incorresponding relation and with an intermediate flat steel strip orplate 8 conforming in shape to the flanges 6 inserted between them, asindicated in Figures 1, 2 and 3. The plate 8 near the open ends of thetube may have arcuate or other shaped edges 9 to permit free inlet tothe air and provide room for using a simple expanding tool to open thetube orifice when inserted in the segment l2. A composite tube socompiled is clamped and the flanges and plate are secured together bySoldering or brazing, but preferably by spot welding, as indicated forexample at the spots I0.

The plate divides the tube into separate passages. If desired, more thanone plate 8 may be interposed, as indicated in Figure 4, some of theplates being dished, so as to sub-divide the tube into a number ofpassages, the air to be cooled being thus split into comparatively thinstrata between walls of good heat conducting material, therebyconsiderably increasing the cooling eiect.

The dished parts i and 2 of the tube are so shaped that their end bendsare tapered so as to ensure a tight fit when the bends are forced intocorrespondingly shaped holes i I in the cylindrical parts or segments l2which form parts of the enclosing casing of the dynamo electric machine.The flanges 6 and the plate 8 are trimmed or tapered, as indicated at20, for the same purpose.

The bends are preferably welded to the segments I2, as indicated at I3,Figure 6, to ensure a further wedging action by the contraction of theWeld.

The plates 8 in conjunction with the flanges 6 form relatively thickcomposite flanges, so that the slots I4 in the segments I2 which receivethem, can be of such width that they can be efficiently punched.

The tubes so constructed are not only eflicient from the cooling pointof view and can be adequately sealed at their flanges, so as to excludedust laden air, but they are strong and rigid.

Figures 8 and 9 illustrate part of an enclosed dynamo-electric machineprovided with cooling tubes I'I of the form shown in Figures 1, 2 and 3.'Ihe machine, as usual, has end shields I8 and I9 and sheet metal casingsegments I2 comprising a casing, an external fan 2I for blowing air overthe outsides of the cooling tubes I'I and an internal fan 22 forcirculating the internal air through the interior of the cooling tubes.As usual, these fans are arranged to direct the flow of air in oppositedirections, as indicated by the arrows 23 and 24, which respectivelyindicate the direction of flow of the cooling air and the internal air,

In order to increase further the cooling surface, the intermediate plate8 may extend beyond the flanges 6 along the whole length and, ifdesired, also beyond the bends at the ends of the tubes, as shown inFigure 7.

I claim:

1. In combination with a dynamo electric machine comprising a casing; acooling tube comprising two sheet metal parts each being dished andhaving a straight portion, two bends and a perimetral flange, anintermediate sheet metal plate, said parts being placed together withtheir flanges in corresponding relation and with said plate between andin contact with said flanges, said flanges and plate being welded orotherwise suitably secured together.

2. The combination with a dynamo electric machine a cooling tube asspecified in claim 1, wherein an intermediate plate, which is adjacentto the open ends of the tube,\is provided with a cut away to facilitatethe insertion of an expanding tool.

3. The combination with a dynamo electric machine a cooling tube asspecified in claim 1, having tapered bends substantially as and for thepurpose hereinbefore set forth.

4. The combination with a dynamo electric machine a cooling tube asspecified in claim 1, having an intermediate plate which extends beyondthe flanges of the dished parts of the tube, substantially as and forthe purposes hereinbefore set forth.

5. In an enclosed dynamo electric machine having slotted cylindricalcasing segments for the reception of cooling tubes, a plurality ofcooling tubes each comprising two stamped sheet metal parts havingstraight portions, bends at the ends and perimetral flanges, and anintermediate metal plate, said parts being placed together with theirflanges in corresponding relation and with the intermediate platebetween and in contact with said flanges, said flanges and plate beingwelded together, and the bends of said tubes being inserted in the slotsof said casing segments and being welded to said segments substantiallyas and for the purpose hereinbefore set forth.

6. In an enclosed dynamo electric machine having a casing provided withopenings for the reception of cooling tubes, a plurality of coolingtubes mounted on said casing and each comprising two sheet metal partshaving straight portions, bends at the ends and perimetral flanges, andan intermediate metal plate, said parts being placed together with theirflanges in corresponding relation and with the intermediate platebetween and in contact with said flanges, said flanges and plate beingfixed together, and the bends of said tubes being inserted in theopenings in said casing and suitably secured thereto.

7. In an enclosed dynamo electric machine having a casing, a pluralityof cooling tube devices mounted on and exterior of the casing andcommunicating with the interior thereof, each of said devices comprisingtwo outer dished metallic plates having flanged parallel edge portionsand two inner dished metallic plates having flanged parallel edgeportions, the flanges of the exterior and interior plates being securedtogether so as to provide an interior fluid passageway and two exteriorfluid passageways surrounding and enclosing the interior passageway,whereby the air passing through all the passageways is split up andthoroughly exposed to the surfaces of the device to increase the coolingeffect.

8. In an enclosed dynamo electric machine having a casing, a pluralityof cooling tube devices mounted on and exterior of the casing, each ofsaid devices comprising two outer dished metallic plates having flangedparallel edge portions and two inner dished metallic plates havingflanged parallel edge portions, the flanges of the exterior and interiorplates being secured together so as to provide an interior fluidpassageway and two exterior fluid passageways surrounding and enclosingthe interior passageway, whereby the air passing through all thepassageways is split up and thoroughly exposed to the surfaces of thedevice to increase the cooling effect.

9. In an enclosed dynamo electric machine having a casing, a pluralityof metallic cooling tube devices mounted on and exterior of the casing,each device comprising an interior fluid passageway and enclosing uidpassageways surrounding the interior fluid passageways, whereby eachcooling tube device is subdivided into a plurality of passagewayscertain of the heat-conducting walls whereof are exposed at both sidesto the air flow to increase the cooling effect.

10. In an enclosed dynamo electric machine having a casing, a pluralityof metallic cooling tube devices mounted on and exterior of the casing,each device comprising an interior fluid passageway and having endportions terminating exterior of the casing and fluid passagewaysenclosing the interior fluid passageway, all of said passagewayscommunicating with the interior of the casing, said end portionsincreasing the area of the cooling surfaces of the device.

PAUL ALPHONSE HUBERT MOSSAY.

